As the amount of communication data has been rapidly increasing due to the proliferation of smartphones in recent years, further expansion of system capacities in cellular communication has been required. To this end, in Release 12 of Third Generation Partnership Project (3GPP), a new architecture for small cells is being currently discussed. In this new architecture, in a small cell disposed within a macrocell, a different frequency band from a frequency band used in the macrocell is used. Accordingly, an advantage of division of cells can be obtained more efficiently.
Topics of discussion with regard to small cells include reduction of power consumption of a base station in a small cell. To this end, for example, causing a base station in a small cell to activate or to be in an idle state (dormant) depending on a state of use of the small cell is considered. As an example, data traffic is extremely small at night in office regions. As another example, in sport stadiums, data traffic is extremely heavy in a specific time zone when an event takes place, but is extremely light in other time zones. As still another example, a base station installed in a home for the purpose of off-loading is not used in most time zones in many cases. As small cells become more widespread and the number of small cells becomes extremely large from now on, the extremely huge amount of overall power consumption can be reduced by cutting power consumption of base stations of small cells. To this end, technologies for reducing power consumption of base stations of small cells have been proposed.
For example, Patent Literature 1 and Patent Literature 2 disclose technologies in which, when it is determined that there is no radio communication terminal in the vicinity of a femtocell, a base station in the femtocell is set to stop receiving radio waves, and when it is determined that there is a radio communication terminal in the vicinity of a femtocell, a base station in the femtocell is set to start receiving radio waves. In addition, Patent Literature 3 discloses a technology in which, based on a position of a mobile terminal device which is obtained through the Global Positioning System (GPS), a small cell which can process communication of the mobile terminal device is specified and power supply to the specified small cell is resumed.